ping at hiway sppeds

[Ironheadmike]

Got a ping at around 65 in fifth . I know the rpm is a little low at that speed . I have a mikuni 42  should I raise the needle or put in a larger intermediate  jet ?

[Piston Broke]

Bike and engine spec is ...

[JamesButler]

More info needed. Stock Evo motor?, how heavy a bike?, what cam?, and what overall gearing ratio are you running? and more importantly, what are the rpm at 65 mph?  All contributing factors among others... 

For example, If gearing is 3.15 :1, then you're at just under 2,700 rpm.  With 3.37 :1, you're just under 2,900 rpm.  On the taller end at 2.925 :1, you're just under 2,500 rpm.  Do you get the ping when cruising at that speed then cracking the throttle to pass?  If so, then the maybe just downshift to 4th...

[Ironheadmike]

Sorry folks . 98 heritage Springer . Stock motor except for carb , ignition  and pipes . Runs down the road fine . It's when I roll the throttle it pings . If  memory serves it's a 2.94 gearing .

[JW113]

I think 3.15:1 gearing was standard after 1995 when the went to the 25/36 primary drive. 65 in 5th is no problem. I have the same gearing, and cruise in steady traffic at 50 no problem. Full throttle at those speeds might be a problem, but not light throttle.

Light throttle ping, or heavy throttle pinging? If light, I'd try upping the mid jet. If heavy, the needle. The needle is metering the main jet, which supplies most of the fuel after about 1/2 throttle.

How did you set your timing? Any chance you're a bit too advanced? Any chance there's a manifold air leak?

-JW

[remington007]

What ignition, settings, and are you running the VOES?

[Hossamania]

Has the carb been rejetted? Idle mixture screw set?
Have you tried fuel from a different station?
And you thought you would just get a straight answer.....

[Reddog74usa]

Also what altitude as high altitude is a bit different.

[JamesButler]

I think 3.15:1 gearing was standard after 1995 when the went to the 25/36 primary drive. 65 in 5th is no problem....
How did you set your timing? Any chance you're a bit too advanced? Any chance there's a manifold air leak?

-JW

  2.925 : 1 is the standard gearing for the '98 Heritage Springer : (36-t clutch sprocket  / 25-t comp sprocket) primary x (65-t rear pulley / 32-t trans pulley) secondary = 2.925 :1, which is the tallest  stock gearing for the Evo motors. 

Therefore at 65 mph in 5th gear, you're spinning just under 2,500 rpm.   While I'd check for a manifold leak, VOES working properly, ignition timing, etc., IMO, that rpm is simply too low for 5th, and you should drop down to 4th gear when twisting the throttle to pass or quickly accelerate, then shift into 5th when you hit your desired speed.  Either that, or go to shorter gearing.  The next logical gearing progression is 3.15 : 1, which is achieved by swapping in a 70-t rear pulley but probably also requires a bigger (136-t) drive-belt.

[rageglide]

VOES would be the first thing I checked.  Dried up plug in the VOES will create a vacuum leak and cause the switch to not work at the same level of vacuum.  Under load if the ignition can't pull timing you'll have pinging issues.

[99 EVO Fatboy Rider]

Check your timing. My 99 Fatboy is geared the same as yours, I have 10:1 compression with my cam advanced and I have no issues with ping. Its actually my best cruising speed. Even at 55 turning 2 grand I have no issues. In my opinion don't change your sprocket size. Fewer RPMs means less engine wear. I've got 98,750 some miles on my bottom end. 65,000 some on my pistons. I'm curious to see what I can get on the bottom end before I'm to worn out to ride

[JW113]

Sorry JB, don't have the book for a '98. Take your word for it though.

I love the taller 2.92 gearing. Only way to go for a Softail IMO. Like Fatboy Rider, never had an issue even down at 55 with steady cruise.

VOES: It is a vacuum make switch. Makes contact ~4 in/Hg, and tells the ECM to advance the timing. Below that, it's open, and ECM is in retard mode. I suppose the VOES could fail in "make" state, but that seems unlikely since there is a spring pushing on the diaphram to hold it open. Easy enough to put an ohm meter on it and see. But if it fails, I'd think it would be stuck in retarded mode, just like not connecting it at all...

My nickel's on too advanced static timing, or too lean at light throttle (air leak or jetting).

-JW

[rageglide]

Valid point JW.   High vac = switch closed, module in Advance mode.  Vacuum leak through the VOES will cause the point where you reach enough vacuum to close the switch to move around or be impossible.  So yeah... Retarded and bad fuel mileage.

[JW113]

OR, as we all know all too well, LEAKY VOES! i.e. air leak. Pop the E-Z Vac on it and check.

-JW

[JamesButler]

Check your timing. My 99 Fatboy is geared the same as yours, I have 10:1 compression with my cam advanced and I have no issues with ping. Its actually my best cruising speed. Even at 55 turning 2 grand I have no issues. In my opinion don't change your sprocket size. Fewer RPMs means less engine wear. I've got 98,750 some miles on my bottom end. 65,000 some on my pistons. I'm curious to see what I can get on the bottom end before I'm to worn out to ride

Your build vs. the OP's stock build is not apples to apples, which kind of reinforces my point.  The stock motor build is dogged down by the taller 2.925 gearing when trying to accelerate in 5th gear at less than 2,500 rpm.

I love the taller 2.92 gearing. Only way to go for a Softail IMO. Like Fatboy Rider, never had an issue even down at 55 with steady cruise.
My nickel's on too advanced static timing, or too lean at light throttle (air leak or jetting).
-JW

Steady cruise at 55 mph is not the issue here, which in 2.925 :1 5th gear is @ 2100 rpm.  And you're doing that with a stock motor?    Anyway, It's cracking the throttle in 5th gear in that sub 2,500 rpm lugging range which is creating the ping...

[Piston Broke]

What happens if you change down a gear and do the same as you are doing?

I think the gear is too low and suspect if you changed it, or changed gear, the problem would go away.

[JW113]

OK feel like a doofus now. Completely missed his post about being in fifth and then rolling the throttle!

Absolutely concur, putting the juice to a tall geared bike in 5th below 75mph, yeah it's going to ping. I had mine set up with a Crane Hi-4, with the advance curve set to the longest slope which put max advance out around 2500rpm. And I also pulled the goop out of the VOES, adjusted it up to ~6 in/hg so the retard would come on at a lighter load. Both helped with pinging with light-ish throttle in 5th, like going down the highway and going up rolling hills.

-JW

[99 EVO Fatboy Rider]

3 years ago my son inlaw bought a 99 fatboy. It only had about 17 thou on it. It was a big dog running 2" drag pipes with just a rejeted carb. Last spring we put a SE breather kit on it then I modified the carb. Then in the fall we put cycle shack m pipes on it. This spring we put the same cam in it I have and same sportster Q module. Then three weeks ago I bumped the main jet up to work with the cam better. Not once did he complain about ping at highway speeds until we changed the cam and didn't have it tmed right. I retarded it by 1.5 lines on the ignition plate and it went away. So just adding my 2 cents worth about checking the timing first

[JamesButler]

...98 heritage Springer . Stock motor except for carb , ignition  and pipes . Runs down the road fine. It's when I roll the throttle it pings...

What ignition was installed and who installed it.  What pipes are your running?

3 years ago my son inlaw bought a 99 fatboy. It only had about 17 thou on it. It was a big dog running 2" drag pipes with just a rejeted carb. Last spring we put a SE breather kit on it then I modified the carb. Then in the fall we put cycle shack m pipes on it. This spring we put the same cam in it I have and same sportster Q module. Then three weeks ago I bumped the main jet up to work with the cam better. Not once did he complain about ping at highway speeds until we changed the cam and didn't have it tmed right. I retarded it by 1.5 lines on the ignition plate and it went away. So just adding my 2 cents worth about checking the timing first

Good story with plenty of details....Unfortunately, the OP wants help with a problem but doesn't want to provide many necessary details, so it's making it harder to figure out.  Although he has not swapped out the stock cam, the ignition timing could very well be the problem, especially if he installed a new ignition module and / or sensor plate. But since he hasn't provided that info or details about how he set the timing, we're just throwing it against the wall and seeing if it sticks...

No matter what the timing, I still think any 700+ lb. bike with a stock Evo motor geared at 2.925 :1 will ping in 5th gear when spinning less than  2,500rpm and then twisting the throttle to pass. 

[Piston Broke]

No matter what the timing, I still think any 700+ lb. bike with a stock Evo motor geared at 2.925 :1 will ping in 5th gear when spinning less than  2,500rpm and then twisting the throttle to pass.

And that's if you can hear it over the primary chain snatching.

The forum needs one of those template forms for asking "support" questions;

model:
cam:
compression:
pipes:
ignition:
gearing:
carb:
other mods:

Too many folks seem to think we run a psychic hotline.

[99 EVO Fatboy Rider]

No matter what the timing, I still think any 700+ lb. bike with a stock Evo motor geared at 2.925 :1 will ping in 5th gear when spinning less than  2,500rpm and then twisting the throttle to pass.

And that's if you can hear it over the primary chain snatching.

The forum needs one of those template forms for asking "support" questions;

model:
cam:
compression:
pipes:
ignition:
gearing:
carb:
other mods:

Too many folks seem to think we run a psychic hotline.

The OP isn't very active to respond for sure. My bike was once stock I never had any issues with ping until I bumped my compression. Then it was needing to be retarted. Bone stock in a head wind two up at 65 on the interstate I couldn't even inch at full throttle one more mph, no ping. I was so disappointed I hated my bike. I started researching and found the nightrider site. It was all up hill after doing the stage 1. I cruised 85 and 90 to Sturgis.

[99 EVO Fatboy Rider]

http://www.mikuni.com/tg_detonation.html

Ironheadmike see if this helps you. If your still reading your post we all can learn by your findings so how about an update. 

[Piston Broke]

I'd start with an EV-13 cam (cheap/more torque/better performing) ... and up-ing the gearing, e.g. next size up rear pulley. You can pick up swops on Ebay etc for very little.

My bet would not be on carburetion.

[99 EVO Fatboy Rider]

If the OP is doing occasionally interstate rides  I understand the thoughts of changing the rear pulley. Other wise he may end up not liking the added Rpms and vibration.

Have any of you been on a Softail geared like mine? Its an easy cruise at 65 all the way to 90. 55 its purring along the engine doesn't even work, no ping from my experience. No lugging just smooth!

I've followed the brothers for 4 - 8 hour rides running 80-90 the entire way numerous times. Not trying to start any issues just not understanding why, I've not nor has my son in law had his issues. Changing the sprocket is seemingly wrong from my experience. From owning the same geared ride he has a great cruiser, yes change the cam then jet for it or now but don't change the smooth interstate - highway ride by changing the sprocket

[JamesButler]

I have 10:1 compression with my cam advanced and I have no issues with ping. Its actually my best cruising speed. Even at 55 turning 2 grand I have no issues. In my opinion don't change your sprocket size. Fewer RPMs means less engine wear. I've got 98,750 some miles on my bottom end. 65,000 some on my pistons. I'm curious to see what I can get on the bottom end before I'm to worn out to ride

Out of curiosity, tell us more about your 10:1 c.r. Evo engine build...
Pistons?
Cam?
Head gasket thickness?
Heads milled how much?
Combustion Chamber Volume?

[Piston Broke]

Head gasket thickness?

Honest question ... 'received wisdom' is that reducing the squish (by reducing the thickness of base and head gasket and even trimming the cylinders) is good at reducing pinging.

But by how much?

(Not how much squish, but how much does it improve combustion/prevent detonation?).

[JamesButler]

Head gasket thickness?

Honest question ... 'received wisdom' is that reducing the squish (by reducing the thickness of base and head gasket and even trimming the cylinders) is good at reducing pinging.

But by how much?

(Not how much squish, but how much does it improve combustion/prevent detonation?).

Reducing gasket thickness and shaving heads and / or cylinders increases comp ratio, which increases chances of pinging, if engine is not properly tuned to accommodate the increased c.r., i.e., properly adjusted Air Fuel Ratio (re-jetted carb), proper cam, proper ignition timing adjustment (more c.r. requires less timing ignition advance).  In addition, shorter gearing (higher ratio) helps offset (spool off) a higher compression ratio which reduces chances of pinging.

Reducing squish to a minimum of .030" for a modified street motor helps promote a better fuel burn and optimal efficiency, which helps reduce chances of pinging...By how much, I do not know...

[Ironheadmike]

OK folks . I have a Hi4 ignition , Freedom Performance exhaust , Mik HSr42 carb . The  voes  is good , I have no leaks . I timed the bike myself and it is right on . I switched the intermediate from a 45 to a 47.5 (next size up) . The ping has stopped but now it runs flat on acceleration when going through the gears from a stop  . Strange . this carb ran great on my 92 springer with the 45 jet . Which had a complete stage three set up . I understand lugging but 2500 is not lugging .  The detonation is happening when I just roll the throttle just to speed up . like from 60 to 65 or 65 to 70 or even just going up hills .

[Hossamania]

Did you test the voes with a vacuum guage and a meter?

[JamesButler]

OK folks . I have a Hi4 ignition , Freedom Performance exhaust , Mik HSr42 carb . The  voes  is good , I have no leaks . I timed the bike myself and it is right on . I switched the intermediate from a 45 to a 47.5 (next size up) . The ping has stopped but now it runs flat on acceleration when going through the gears from a stop  . Strange . this carb ran great on my 92 springer with the 45 jet . Which had a complete stage three set up . I understand lugging but 2500 is not lugging .  The detonation is happening when I just roll the throttle just to speed up . like from 60 to 65 or 65 to 70 or even just going up hills .

Overall Gearing Ratio for the '92 Springer was 3.37:1...

[Burnout]

You can't control detonation with fuel. You will wind up over-fueled.
You need to back off the timing a little bit at a time until the problem goes away.
The alternative is to use thicker head gaskets, but that will take away squish which helps with detonation .

If you have to a better solution is to use heads that have not been shaved or relieve the chamber to lower compression.

Another consideration is to retard the cam timing so the intake valve closes later to reduce the dynamic C/R.

Take a look at your package and see which area is the culprit instead of trying to band aid it.

[remington007]

You may need to change the setting of the VOES unit. Have you checked the vacuum setting of the switch? IE make it switch to the high load curve sooner. 

[JW113]

You can't control detonation with fuel. You will wind up over-fueled.

Not IF the AFR was too lean in the first place, then more fuel will indeed help. But if not too lean, then yes, more fuel will hurt.

So when I've had this kind of problem in the past, and correcting for everything else, the fix was always: more cam.

Mike, since you have a Hi-4, have you tried dialing the advance delay up to the max?

-JW

[Burnout]

A slower advance curve can help, just taking out a couple of degrees of spark can sometimes solve this depending on the level of detonation present.

Of course a setup cannot be made idiot proof AND deliver maximum performance. You can't just grab a big handful of throttle at low rpm in high gear......

[Hossamania]

What grade of fuel are you running? Have you tried switching brands of fuel?
It could also be caused by a build up of carbon on the pistons.
Has it done this since you got it?
How many miles on the motor?

[Ironheadmike]

I used a multi vac and a multi meter to check  the VOES it turns on just under 5 . I plan on doing some engine work this winter ,but now I want to just ride the damn thing . I'll retard the timing a degree or two tonight when I get home and see what happens .Won't changing the pulleys out mess with your speedo ? I know my 92 had 337 gearing and this on has 292 but still I can't see how getting the rpms up will stop detonation  when it does it at any speed when you just lightly twist the throttle .

[tomfiii]

The voes setting might have to be changed to dresser setting due to weight of model(I see yours is set higher already) as light adding of throttle does not lower vacuum enough to trigger voes,you have to give more throttle or go easier on feeding throttle. I retarded my timing 2 degrees and everything got happy.

[remington007]

I would try a setting 6-7 on the VOES. Reseal the screw if you change it or there will be a vacuum leak.

[Ironheadmike]

I think it's strange that the bike only has 12000 miles on it and it has these problems . Grant it, it sat for 10 years , but the carb sat with gas in it all these years and pitted the hell out of the lower part and the accelerator pump . That is why I'm using the mikuni . I'll put the 45 jet back in ,retard the timing 2 degrees tonight and see what happens . I've been wrenching on these motors  (EVO'S) for over 30 years and this is the first time they have gave me this kind of headache .

[SixShooter14]

Can someone answer a greenhorn question for me?

How does one recognize detonation? Is it obvious?

Just curious. Thanks

[Burnout]

You may have a junky ignition
Check timing on both cylinders?

[Burnout]

Can someone answer a greenhorn question for me?

How does one recognize detonation? Is it obvious?

Just curious. Thanks

Anywhere from a light valve noise to marbles in a mason jar.

[JamesButler]

I'll retard the timing a degree or two tonight when I get home and see what happens.  Won't changing the pulleys out mess with your speedo? I know my 92 had 337 gearing and this on has 292 but still I can't see how getting the rpms up will stop detonation when it does it at any speed when you just lightly twist the throttle .

No, changing the pulleys will not mess with the mechanical speedo. 

IIRC, initially you detonation problem occurred when twisting the throttle in 5th gear at under 2,500 rpm.  Now you're implying that if you're at 3,000 rpm in 5th gear, which is @ 79 mph with 2.925 :1 gearing, and you lightly twist the throttle, then you get some pinging?.  If that's the case, then it seems more like a timing or VOES issue. 

BTW, What exhaust pipes are you using?  How's your oil consumption? If low, maybe a sticky valve not closing properly, causing more heat leading to a ping?

[JW113]

He says it's a 1998. So, electronic speedo. Isn't the sensor for that in the trans? Which means changing pulley, yes will mess up speedo. Unless there is a way to "flash" something to correct it. Sorry, no knowlege of those years Evo speedos.

I think he is saying he's not pegging the throttle in 5th gear, but rather cruising along at 65, and gives it a bit of juice to speed up to 70 or so. And it pings. Been there, done that. Cam....

Mike, I don't recall if you did a cold cranking compression test. Be interesting to see how many psi it pops. That would maybe help diagnose.

-JW

[JamesButler]

He says it's a 1998. So, electronic speedo. Isn't the sensor for that in the trans? Which means changing pulley, yes will mess up speedo. Unless there is a way to "flash" something to correct it.

I think he is saying he's not pegging the throttle in 5th gear, but rather cruising along at 65, and gives it a bit of juice to speed up to 70 or so. And it pings. Been there, done that. Cam....

Mike, I don't recall if you did a cold cranking compression test. Be interesting to see how many psi it pops. That would maybe help diagnose.

-JW

Yes, you are correct re the electronic speedo...he had mentioned a '92 model in an earlier post, and I confused it with his current model. There are aftermarkets who make speedo re-calibrators when pulleys are swapped out.  Baker transmission is one, IIRC...

In my experience with 2.925 :1,  The pinging zone occurred in highest gear as high as 2,800 - 3,000 rpm when cruising then accelerating to pass or climb a hill, and that was with a lighter bike ('99 FXR3). It had a compression bump which was corrected down to @ 9.00 :1 with a mild cam.

However, in the OP's situation, one of his initial posts describes the '98 Heritage Springer as having a stock build, all except for "carb, ignition module and exhaust", so how could the stock cam timing be the culprit?

[JW113]

This is why I was inquiring about the CCP. Just trying to get another data point. Stock cam has pretty short duration, early intake close. So yeah, in a tall gear, probably going to ping in the lower rpms. Even in hot rod form, I fought pinging in the lower rpms as well, and did all the usually tricks like Hi-4 set to longest delay ramp, readjusted VOES for a higher vacuum, etc. All helped somewhat but no real cure. Was on a road trip through Iowa one time, running an S&S 561 cam. Out on the backroads in the midwest, about the only gas we could find was that gasahol crap from these Caseys general stores, which seemed to have driven out every major brand gas station in the state. Bike pinged like a reel of Black Cats at the slightest bit of throttle. Got home, replaced with a Crane High Roller 510, no more problems. Even in 5th. So stock or no, if everything else he inspects checks out OK, and still wants to cruise in 5th below 75, then maybe a cam with a little bit more intake duration might help.

Just sayin'!


-JW

[JamesButler]

This is why I was inquiring about the CCP. Just trying to get another data point. Stock cam has pretty short duration, early intake close. So yeah, in a tall gear, probably going to ping in the lower rpms. Even in hot rod form, I fought pinging in the lower rpms as well, and did all the usually tricks like Hi-4 set to longest delay ramp, readjusted VOES for a higher vacuum, etc. All helped somewhat but no real cure...Even in 5th. So stock or no, if everything else he inspects checks out OK, and still wants to cruise in 5th below 75, then maybe a cam with a little bit more intake duration might help.
Just sayin'!

-JW

Problem with only swapping in a cam with a later intake closing (w/out a compression bump) to a stock Evo is that you are shifting the "power zone" of the bike to the right - meaning the cam "comes on" later i.e., at a higher rpm.  So, if you're preferred riding style is cruising in the mid to high 2000's  rpm, then aren't you just further "dogging down" the bike's performance - kind of like just adding more fuel to the AFR mix and / or  staying with the tallest gearing? 

[JW113]

There's no doubt the torque will go down a little below 2500, though I don't think more than a handfull ft/lbs. That's the effect of bleeding off some of the CCP with more intake valve timing. Not suggesting to put a 262 degree cam in, perhaps somthing with 5-8 more degrees than stock. His '98 probably has the "N" cam, i.e. 30deg ABDC. So, something around 35deg? EV-27?

All a game of trade-offs, no doubt. But pinging, especially sustained, will kill the motor.

-JW

[JamesButler]

There's no doubt the torque will go down a little below 2500, though I don't think more than a handfull ft/lbs. That's the effect of bleeding off some of the CCP with more intake valve timing. Not suggesting to put a 262 degree cam in, perhaps somthing with 5-8 more degrees than stock. His '98 probably has the "N" cam, i.e. 30deg ABDC. So, something around 35deg? EV-27?

All a game of trade-offs, no doubt. But pinging, especially sustained, will kill the motor.

-JW

According to the Mikuni site http://www.mikuni.com/fs-tuning_guide.html (copy & paste), which was referenced in an earlier post, 1º of intake closing is 120 rpm, i.e., the power zone is moves to the right / 120 higher rpm with each added degree of intake closing.  Therefore, swapping from a  30º intake closing cam to a 35º intake closing cam would shift the power zone @ 600rpm higher which provides too much cam and poorer mid-range performance, without any c.r. bump.  The EV-27, which BTW closes at 36º, loves 9.5 :1 mechanical c.r., while stock c.r is a whopping 1-pt lower at 8.5 : 1.

For someone who seems to ride mostly in the mid to high 2000's rpm, not only would he rarely, if ever, feel the "fun factor" of the EV-27 but he'd be feeling less of  a "fun factor" than compared to the dogged stock "N" cam which will at least have some effect in his riding range.  Exactly why I suggested he shorten his gearing to at least @ 3.15 :1, which will serve to definitely move him closer (left) into his cam's rpm power zone and his riding style while also potentially spooling him out of the ping zone...

If anything, instead of swapping in a new cam, why not simply retard the stock "N" by a degree or two?  However with the stock motor, I don't think his pinging problem is a cam timing problem...

I think it's strange that the bike only has 12000 miles on it and it has these problems . Grant it, it sat for 10 years , but the carb sat with gas in it all these years and pitted the hell out of the lower part and the accelerator pump . That is why I'm using the mikuni . I'll put the 45 jet back in ,retard the timing 2 degrees tonight and see what happens.

Just spitballing here, but referencing the highlighted bit of info from one of your prior posts saying that the bike "sat for 10 years", which maybe suggests that you bought this bike pre-owned, recently.  If so, are you sure the Evo is stock?  Maybe heads were shaved by a previous owner and thinner head gasket / base gaskets swapped in to bump up the c.r?  And you're sure the cam is stock?

[JamesButler]

     

[Ironheadmike]

The bike is/was bone stock.  I just picked it up about a month ago . I got it from an old man in his eighties . he bought it new the day he retired . It sat for about ten years because he couldn't pick it up off of the kickstand anymore .  It ran kind of rough when I got it and I figured it was due to sitting so long and it needs some bugs worked out it .  I probably only have a couple of weeks left to ride until the snow flies . Then I'll tear into it .  I have a fresh set of Scottsmans heads sitting on the shelf along with a fresh set of barrels and matching 10:1 pistons I'll be throwing on it . Also I plan on putting in a W6 cam . So a mild build . This combo works really well for me on my other bikes . I just wanted to get in a few more rides . I think I'm going to go with a 24 tooth comp sprocket to get a little more pull I don't mind the vibration of the higher rpms . I did mention a 92 because I took the Mikuni off of that and put it on  the 98 . 

[JohnFlorida]

I didnt read all the responses but just in case no ones mentioned it. Heavy carbon deposits on your pistons will give you pinging at hiway speeds.

[Ironheadmike]

I thought of that , but I don't own a scope to check it out .

[Hossamania]

Easy enough to try and decarbonize it by spraying some water through the intake.

[Burnout]

Bad ignition pickup.

[JamesButler]

I didnt read all the responses but just in case no ones mentioned it. Heavy carbon deposits on your pistons will give you pinging at hiway speeds.

So in this situation - a stock Evo motor with only 12K miles what could be the causes for heavy carbon deposits? Leaking / worn valve seals not seated properly due to sitting for 10 years?

[Hossamania]

Carbon could easily build up in that amount of miles if ridden constantly low in the rpm's, loading up the motor.

[JamesButler]

The bike is/was bone stock.  I just picked it up about a month ago . I got it from an old man in his eighties . he bought it new the day he retired . It sat for about ten years because he couldn't pick it up off of the kickstand anymore .

Carbon could easily build up in that amount of miles if ridden constantly low in the rpm's, loading up the motor.

Makes sense.  With only @ 12K miles in 10 years, as it sat for the last 10 years, ridden by a man in his late 60's and early 70's could suggest it wasn't ridden hard and constantly in low rpm...

Found this earlier thread in HTT.  Replies #5 and #6 (one being by a noted engine builder) agree with you...

http://harleytechtalk.com/htt/index.php?topic=37284.0

[Ironheadmike]

This very well could be the problem . I was own by an old dude who seamed very cautious when he rode by the way he talked .

[Piston Broke]

I didnt read all the responses but just in case no ones mentioned it. Heavy carbon deposits on your pistons will give you pinging at hiway speeds.

I'm not actually very clear on the various alternative terms; e.g. pinking, pre-ignition, detonation.

On a bike that has not had its ass kicked regularly, carbon deposits on the pistons act like little hot coals igniting the fuel mix.

But the rest can include anything from piston top deflections, to actual piston-eating explosions.

Combustion is meant to be a burn, not actually a big bang.

[JamesButler]

I have a fresh set of Scottsmans heads sitting on the shelf along with a fresh set of barrels and matching 10:1 pistons I'll be throwing on it . Also I plan on putting in a W6 cam . So a mild build . This combo works really well for me on my other bikes . I just wanted to get in a few more rides . I think I'm going to go with a 24 tooth comp sprocket to get a little more pull I don't mind the vibration of the higher rpms ...

What brand of 10:1 c.r. pistons? 

Also, won't swapping in a 24-T comp sprocket require swapping in a primary chain with one less link?  Up until '93 the stock primary was 37-t clutch / 24-t comp sprocket.  In '94, due to stricter emissions standards and for easier starting, the MoCo changed the stock primary to a 36-t clutch / 25-t comp sprocket. In both cases the 61-t primary chain was stock, as 36 + 25 = 61, and 37 + 24 = 61. 

BTW, with 2.925:1 overall gearing ratio, the rpm would only increase a little more than 100 rpm at 65 and 70 mph by swapping in the 24-t comp sprocket, which is negligible...

[Piston Broke]

I don't know about the chain swop but Baker has a table which tells you what works with what. Swopping the shoe around used to allow even a 23T but left a pretty nasty chain angle.

Big Boys website has a useful Gear Ratio calculate into which you can plug in all the alternatives and find out the results, e.g. going up to a 70T rear would drop 24.0 per 1,000 rpm versus stock 25.8 per 1,000 rpm.  Therefore, 70 mph at 2,713 rpm versus 70 at 2,917 rpm.

Going down to a 30T front pulley would have much the same effect (2,892 rpm) and probably keep the same belt.

(Rough calculation ... but it means that it's not going to be the end of the world).

[Ironheadmike]

Well folks . I went a bought a bore scope and the pistons are caked with carbon . So I found the culprit . I sprayed water through the  carb twice and then I used seafoam for a third cleaning . Thanks for all your input .
 

[Hossamania]

Sweet. The oil should probably be changed to get out any contaminants that have gotten into it from the cleaning process.
Glad you got it sorted out.

[JamesButler]

Well folks . I went a bought a bore scope and the pistons are caked with carbon . So I found the culprit . I sprayed water through the  carb twice and then I used seafoam for a third cleaning . Thanks for all your input .

But what caused the excessive carbon build-up?  A result of detonation caused by the previous constantly riding at too low of a RPM in 5th gear?   

[Hossamania]

Well folks . I went a bought a bore scope and the pistons are caked with carbon . So I found the culprit . I sprayed water through the  carb twice and then I used seafoam for a third cleaning . Thanks for all your input .

But what caused the excessive carbon build-up?  A result of detonation caused by the previous constantly riding at too low of a speed in 5th gear?

That would be my guess, older gent riding much too gently.

[Piston Broke]

But what caused the excessive carbon build-up?  A result of detonation caused by the previous constantly riding at too low of a RPM in 5th gear?

Likely the too low riding and lugging the throttle open then, i.e. unburnt fuel/too rich running at that point in the carburetion.

Have a look at an engine that's run at higher rpm most of the time.

There's also a "feature" (it's not a "bug" it's a feature) on the rear because of H-D whacky intake/degrees between cylinders, e.g. the rear is worse. Basically, you've got two different engines with one carburetion setting.

I wonder if your head breather also vents oil back into the carb?

Ditto, oil could be working it's way past the rings and down the side of the guides if they are worn?

[Hossamania]

Agreed on the breather running into the intake, venting to the ground or a catch can would help eliminate carbon build up.

[JW113]

Leaving the enrichener on too long, combined with lots of short hops...

-JW

[Ironheadmike]

I think it the old man I bought it from was just putting around on it on the back roads . He said he never had it on  the hiway or freeway . When the rain/snow stops , hopefully, I can take it out .

[JamesButler]

But what caused the excessive carbon build-up?  A result of detonation caused by the previous constantly riding at too low of a RPM in 5th gear?

Likely the too low riding and lugging the throttle open then, i.e. unburnt fuel/too rich running at that point in the carburetion.

I wonder if your head breather also vents oil back into the carb?

Ditto, oil could be working it's way past the rings and down the side of the guides if they are worn?

All stock Evos after '92 were head breathers that fed to the intake.  The bike in question is said to be a stock '98 Heritage Springer, so we can assume that it's set up to vent oil back into the intake.

Agreed on the breather running into the intake, venting to the ground or a catch can would help eliminate carbon build up.

I know it's less messy, but could you guys elaborate more on why the breather running into the intake causes more carbon build up than (pre-'93) bottom breathers or head breathers that are modified to vent to the ground (atmosphere) or into a catch can?   

[Hossamania]

The breathers pull oil mist from the top of the motor, out of the heads. They are connected to the intake, in the filter, and sucked into the carb and burned in the combustion process. The suction created by the carberator actually helps pull the mist out of the heads. By sending that oil thru the carb, into the cylinders, to be burned along with the fuel and air, it tends to not burn as cleanly as it could without the oil mixed in. This causes a build up of carbon, unburnt fuel and oil deposits.
By rerouting the vents to the ground or can, that oil is eliminated from the combustion process.

[JamesButler]

The breathers pull oil mist from the top of the motor, out of the heads. They are connected to the intake, in the filter, and sucked into the carb and burned in the combustion process. The suction created by the carberator actually helps pull the mist out of the heads. By sending that oil thru the carb, into the cylinders, to be burned along with the fuel and air, it tends to not burn as cleanly as it could without the oil mixed in. This causes a build up of carbon, unburnt fuel and oil deposits.
By rerouting the vents to the ground or can, that oil is eliminated from the combustion process.

Thanks.  I know Screamin' Eagle makes a kit for the 80" Evo motors.  Comes with a cross-over tube that connects the breathers, with a hose that runs down from the tube.  Crush washers and backing plate also included...

Would you happen to know a similar kit is made for S&S V111 c.i motors, or if something similar could be done with the head breathers of bigger S&S motor to route the mist to the ground / atmosphere?

[JW113]

All stock Evos after '92 were head breathers that fed to the intake.  The bike in question is said to be a stock '98 Heritage Springer, so we can assume that it's set up to vent oil back into the intake.

I know it's less messy, but could you guys elaborate more on why the breather running into the intake causes more carbon build up than (pre-'93) bottom breathers or head breathers that are modified to vent to the ground (atmosphere) or into a catch can?   

Uh, hold on. The head breather set up did indeed have a tube system to vent into the air cleaner, but so did the '92 and earlier. The was a tube that ran from the cam chest up to the air cleaner. BOTH, in factory stock form, vented to the air cleaner. Many of us simply ran the vent hose to the ground after installing aftermarket air cleaners. Catch can??? Who bothers with that?

I don't think the crankcase vent has a lot to do with carbon build up. If it's oil related, more likely past the rings or valve guides.

-JW

[JamesButler]

All stock Evos after '92 were head breathers that fed to the intake.  The bike in question is said to be a stock '98 Heritage Springer, so we can assume that it's set up to vent oil back into the intake.

I know it's less messy, but could you guys elaborate more on why the breather running into the intake causes more carbon build up than (pre-'93) bottom breathers or head breathers that are modified to vent to the ground (atmosphere) or into a catch can?   

Uh, hold on. The head breather set up did indeed have a tube system to vent into the air cleaner, but so did the '92 and earlier. The was a tube that ran from the cam chest up to the air cleaner. BOTH, in factory stock form, vented to the air cleaner. Many of us simply ran the vent hose to the ground after installing aftermarket air cleaners. Catch can??? Who bothers with that?

I don't think the crankcase vent has a lot to do with carbon build up. If it's oil related, more likely past the rings or valve guides.

-JW

Yes, with the '92 and earlier bottom breather models, it was easier to run the vent hose to the ground, as no kit was required.  The point I was trying to address was that in addition to the recent previous posts in this thread regarding the head-breather venting system, I've read in a previous HTT thread (I'll try to find it and paste the link) that with modified Evos, the stock head breather system venting into the air cleaner contributed to carbon build up. 

To take that thought a step further, since the S&S V111 is basically a super modified EVO, I was wondering if it wouldn't be better to re-route the stock oil venting system from the air cleaner to the atmosphere, especially when touring multiple 600+ mile days in the 100º+ heat.  And if so, is there a breather kit out there for the S&S V111 motor?

You however disagree with this and suggest directing the focus on faulty rings or valve guides. And I totally see that point. 

My counterpoint: In a higher compression motor, is it possible that the stock head-breathing system, (with its oily air-fuel mixture byproduct that creates a hotter-dirtier combustion), would precede and actually cause the valve guide problem, i.e., gunk up a valve guide and combustion chamber due to the hotter-dirtier combustion and thus eventually cause a heat and oil consumption problem? 

Kind of like a chicken / egg quandary.  Or at the very least creating a vicious cycle...Or am I completely off-base here ? 

"...Catch cans? We don't need no stinking Catch cans!"    

[Burnout]

Enough with the over analyzing blowby based carbon buildup.

Although unarguably a contributing factor not a significant source.

More likely too rich idle mix, improper use of the enrichener, short trips, lack of heat, never run hard enough to burn off unburned stuff, or operated in a poor state of tune for a long time.

The only argument for not dumping blowby on the ground is voiced by the EPA.

Frankly if your motor is dumping enough oil in the intake to foul the filter or affect combustion THERE IS SOMETHING WRONG WITH YOUR MOTOR!

[Hossamania]

I tend to disagree with the statement that venting the breather into the carberator does,not contribute to carbon build up. Even when the motor is in good operating condition, the oil mist being pulled into the combustion chamber builds up and coats everything, including making the carberator dirtier, getting on the intake valve, etc.
Anything that can be done to eliminate that oil is a good thing.

[JamesButler]

Enough with the over analyzing blowby based carbon buildup.

Although unarguably a contributing factor not a significant source.

More likely too rich idle mix, improper use of the enrichener, short trips, lack of heat, never run hard enough to burn off unburned stuff, or operated in a poor state of tune for a long time.

Frankly if your motor is dumping enough oil in the intake to foul the filter or affect combustion THERE IS SOMETHING WRONG WITH YOUR MOTOR!

Overanalyzed, perhaps.  But that's what we nerds with Harleys do on these forums.   

We all seem to agree that it is a contributing factor.  Some, more than others.  Your view is that if everything else in the motor is up to standard, then it's a non-factor.

However, if there is a problem with the motor, then it would seem to help snowball the issue / intensify the problem, so symptoms would occur much sooner than later.

I tend to disagree with the statement that venting the breather into the carburetor does not contribute to carbon build up. Even when the motor is in good operating condition, the oil mist being pulled into the combustion chamber builds up and coats everything, including making the carberator dirtier, getting on the intake valve, etc.
Anything that can be done to eliminate that oil is a good thing.

Would you know if there's a kit or what would be required to change the S&S V111 c.i. motor (Super E carb) internal venting system to an external venting system?  Looking for an aftermarket fix for an aftermarket motor...

I always prefer to vent externally.  Internalizing issues always leads to health problems...

[Hossamania]

Sorry, I am not familiar with the breather system on that motor, but by studying it a bit, perhaps a home fix could be set up, somehow maybe drilling and tapping for new routing of the breathers.
If you have some pictures, maybe something could be suggested.
Or, maybe post this question in the General section, it may get more looks.

And I try not to internalize issues, I let people know exactly what the issue is. Then it's their problem.....

[JamesButler]

Sorry, I am not familiar with the breather system on that motor, but by studying it a bit, perhaps a home fix could be set up, somehow maybe drilling and tapping for new routing of the breathers.
If you have some pictures, maybe something could be suggested.
Or, maybe post this question in the General section, it may get more looks.

And I try not to internalize issues, I let people know exactly what the issue is. Then it's their problem.....

Been doing a search on HTT and found a thread where a members posted photos of home fixes.
http://harleytechtalk.com/htt/index.php?topic=47207.0

[JW113]

Climbing up to the 10,000 foot level for look...

EVERY internal combustion engine made in the last <how many? 40-50 years?> vents the crankcase into the intake system. Go look at your car or truck motor. Yes, PVC line going into the intake manifold. This issue is NOT exclusive to Harley-Davidson. I'm sure most of you are not worrying about carbon build up in your car motor because the crankcase is being vented to the intake system. Are you?

That little bit of "oil-mist" that gets sucked into a Harley air cleaner gets burned in the cylinders. That's the whole point. If the motor gets used, driven at speeds high and long enough to burn it all off, no problem! It's the short hops, never getting the motor really hot, that causes carbon build up. That, and the worst of the worst, BABYING the machine and never giving hard full throttle pulls once in a while. THAT alone blows that crap outta there. And as mentioned, jetted too rich (yes you S&S guys), or using the enrichener longer than needed (yes you HD newbie guys).


Whew. Glad I got that off my chest.


-JW

[SixShooter14]

Not my old truck....I broke that hard breather line off trying to change my air filter...oops.

And I'm a HD newb, and I have a S&S E.....I guess I'm just screwed.....but I do run the sh....crap out of it once she's warm.

[JW113]

Hey nothing wrong with being a newb, wear it with honor. We all started about as a newb, and some learned the hard way what works and what don't. The ones that didn't ended up with carbon build up on their pistons.


-JW

[JamesButler]

Climbing up to the 10,000 foot level for look...
Careful, the air is thin up there. You'll need to re-jet...

EVERY internal combustion engine made in the last <how many? 40-50 years?> vents the crankcase into the intake system.
Since 1978, I believe, so @ 38 years - give or take.

Go look at your car or truck motor. Yes, PVC line going into the intake manifold. This issue is NOT exclusive to Harley-Davidson.
I drive a Tesla, but I'll take your word for it.

I'm sure most of you are not worrying about carbon build up in your car motor because the crankcase is being vented to the intake system. Are you?
I am, now. 


That little bit of "oil-mist" that gets sucked into a Harley air cleaner gets burned in the cylinders. That's the whole point. If the motor gets used, driven at speeds high and long enough to burn it all off, no problem! It's the short hops, never getting the motor really hot, that causes carbon build up. That, and the worst of the worst, BABYING the machine and never giving hard full throttle pulls once in a while. THAT alone blows that crap outta there. And as mentioned, jetted too rich (yes you S&S guys), or using the enrichener longer than needed (yes you HD newbie guys).
If anything my S&S Super E is jetted too lean, and my problem occurred during a 2+week, 5,300 mile touring trip where the motor was run at 3,300 - 3,500 for several tankfulls a day (600 -700 miles per day for a few days straight). Pretty certain the motor got hot enough in the east coast and midwest late July to early-mid August heat.

Pulled this excerpt from a blow by thread in another forum: http://www.cvoharley.com/smf/index.php?topic=14309.0[/url]

Reason for Oil Blow By:  More air is displaced by the ascending and descending pistons when a 95" and larger kits have been installed, simply because there's bigger pistons moving up and down.  Sustained high rpm riding aggravates blow by because more oil is being pumped into the engine since the pump is turning faster.  The rocker boxes become overwhelmed with too much oil that it cannot separate the oil from the escaping air.  Some stock displacement engines have oil blow-by problems even when ridden moderately, but that is not the norm.  Blow-by does not happen immediately because the oil buildup that causes it takes time to occur.  That's why blow-by sometimes doesn't occur until after sustained high-speed riding.


Whew. Glad I got that off my chest. 
AHHH, The benefits of externally venting...


-JW

[Ironheadmike]

Harley didn't start venting through the head til mid year of 1992 .

[JamesButler]

Harley didn't start venting through the head til mid year of 1992 .

We know. 

The very valid point that JW and others in this thread want to make clear is that head breathers and crankcase breathers both are designed by the MoCo to vent the oily mist into the air-cleaner, which is then burned off internally in the combustion chamber then blown out through the exhaust. 

He also stated very clearly that whether head or crankcase breathing, the internal venting system has been used for 40+ years not only by the Moco, but also by the car industry, as it is the accepted practice because not only does it work very well, especially on stock builds, but it satisfies EPA and emissions standards.

The two complaints that others have about the internal venting system, whether head breathers or crankcase breathers:
1) an oily mess sometimes collects at the air cleaner area, then drips / sprays onto the bike, pant leg, boot, passenger, etc. 

2) for bigger / more powerful than stock or modified stock motors, which are run hard at higher rpm over a sustained time, the oily mist not only makes the above-described external mess but also actually creates an internal mess due to a hotter, sloppier, inefficient burn in the combustion chamber, which eventually contributes to a gunky build in the combustion chamber, which could lead to  a sticky valve among other various problems, which then leads to a messier inefficient burn, heat problems, pressure problems, carbon build-up, etc.  Kind of like a snowballing effect.  The cure then is to re-route the internal venting system, i.e., disconnect the breather line going into the the air-cleaner, whether it's coming from the crankcase or head breathing, then put a catch can, filter, valve onto that re-routed line or simply lead the line towards the ground (atmosphere).

[JW113]

Stock engine, with stock cam/heads/etc/etc, don't really make much usable torque past ~3500rpm. Most people tend to shift soon and keep the rpms down.

Hop it up a bit, Stage 2/3/to-the-moon-alice, and now serious torque up to the point the motor flies apart.

Consider a hand mixer. Put it in a bowl of milk, and start cranking away as fast you can. A little might fly out of the bowl, but probably not a lot. There's your stock motor.

Now grab an Oster blender, dial it up to 11, stick it in the bowl of milk, and pull the trigger. Then get out the mop, bucket, sponges, and start cleaning off the walls, ceiling, and floor. That's your hot rod motor at redline.

How high and often you wind the motor up is directly proportional to how much oil froth the crank & it's mechanical buddies whip up inside the motor. And as we all know, the more you hop up the motor, the more likely you are to take advantage of that evil high rpm torque. That's the whole point, right?

So yes, stock motors run just fine venting the crank to the air cleaner. I think I got 120K on my stock evo, no real issues other than worn out at that point. After I hopped it up with heads, stroker crank, cam, etc, yeah it got a bit messy in the air cleaner so just dumped the vent line to the ground. Problemo-solved.



-JW

[rageglide]

Don't run the breathers to the intake.  Don't do it.

Just because V8s do it doesn't mean you should.  It's an EPA thing.  If you're worried about oil mist blowing on the tires or wherever, use a catch can.  If you're getting that much oil carry over to worry about wetting your tire - fix your blow by issues.

V8s (or whatever auto engine) doesn't have a pool of oil ABOVE the vent.  The vent for a auto PVC system sits in the valve cover with a deflector in between splashing oil and the upward pointed vent.  Evos and TCs have a 1/8" ledge (in stock form) between a puddle of oil which pours into the vent if the oil accumulation is excessive and gravity moves it toward the exit.  It's a "Potty mouth" design.  Crankcase breather with a krank vent or similar is better.  Head breather is aesthetic and a more "tamper proof" design.

Also, if you use James umbrellas in your head breather, forget it... they're way too stiff to ever obtain a decent seal.